Thin Image Capturing Apparatus

ABSTRACT

A thin image capturing apparatus includes a circuit substrate having at least one electronic component, a light sensing element packaged onto the circuit substrate, and a camera lens installed onto the light sensing element for capturing images.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image capturing device, and moreparticularly to a thin image capturing apparatus and a manufacturingmethod thereof.

2. Brief Description of the Related Art

In some of present notebook computers available in the market, an imagecapturing device is installed at the top of a screen to capture imagesfor communications or video records. As notebook computers tend to bedeveloped with a light, thin, short and compact design and the pixelrequirement of the image capturing device becomes increasingly higher,the thickness of a casing of the notebook computer can be as thin as 5mm only, and the space for installing a 3 mega-pixel image capturingdevice (including a camera lens) is only 3.5 mm. As to the concurrentway of assembling image capturing devices, the overall thickness of the3 mega-pixel image capturing device becomes greater and results in abottleneck for assembling an image capturing device with a larger pixelvalue into a 3.5 mm-space, so that major manufacturers improve thepackaging technology to overcome this problem with full commitment anddedication.

With reference to FIG. 17 for a conventional packaging structure 90 ofan image capturing device, the packaging structure 90 comprises a lightsensing element 900, a transparent glass 901, and a printed circuitboard 902, wherein the transparent glass 901 includes a circuit 903coupled to a signal output, and electrically coupled to a contact point904 of the light sensing element 900, and sealed with an adhesive 905,and another side of the transparent glass 901 is electrically coupled tothe printed circuit board 902 to form the packaging structure 90.Compared with the packaging structure of an earlier stage, thispackaging structure 90 has reduced the overall thickness, but when thecamera lens 906 is installed onto the printed circuit board 902, theposition of the camera lens 906 must be aligned precisely with a sensingarea of the light sensing element 900. For a small discrepancy, poorimages may result, and thus the packaging structure 90 must becalibrated manually for precisely installing the camera lens 906 at acorrect position of the printed circuit board 902, and the operation isvery troublesome and impractical.

With reference to FIG. 18 for another packaging structure 91 of aconventional image capturing device, the packaging structure 91 alsocomprises a light sensing element 910, a transparent glass 911, and aprinted circuit board 912, wherein the printed circuit board 912 has anopening 913, and the transparent glass 911 is installed onto the lightsensing element 910, and the light sensing element 910 is installed ontoa side of the transparent glass 911 and attached onto the substrate 912by an adhesive 914. Meanwhile, a solder pad 915 of the light sensingelement 910 is electrically coupled to the printed circuit board 912.Now, the transparent glass 911 is situated inside the opening 913 of theprinted circuit board 912 for reducing the overall thickness toconstitute this packaging structure 91. Compared with the foregoingpackaging structure 90, this packaging structure 91 has a smallerpackage size, but this packaging structure 91 still has the same problemas the foregoing packaging structure 90 that requires a manualcalibration to precisely install the camera lens 916 onto printedcircuit board 912, and thus both packaging structure 90 and packagingstructure 91 have not been used in actual productions yet.

With reference to FIG. 19 for another packaging structure 92 of aconventional image capturing device, the packaging structure 92 alsocomprises a light sensing element 920, a transparent glass 921, aprinted circuit board 922, and a heat dissipating substrate 923, whereinboth light sensing element 920 and printed circuit board 922 areinstalled onto the heat dissipating substrate 923, and the printedcircuit board 922 has an opening 924 for exposing the light sensingelement 920, and the light sensing element 920 is electrically coupledto the printed circuit board 922 by a connecting wire 925, and thetransparent glass 921 is installed onto two pads 926 and disposed at thetop of the light sensing element 920, and a camera lens 927 is installedat the transparent glass 921 to constitute the packaging structure 92.However, this packaging structure 92 requires an additional installationof the heat dissipating substrate 923, so that the overall thickness ofthe packaging structure 92 is relatively large, and requires furtherimprovements.

In view of the aforementioned problems, it is a key point for thepresent invention to find a way of reducing the volume of the imagecapturing device and precisely aligning the camera lens precisely duringthe manufacture, while the notebook computers tend to be developed witha smaller size and an enhanced pixel value of the image capturingdevice.

SUMMARY OF THE INVENTION

It is a primary objective of the present invention to overcome theaforementioned problems by providing a thin image capturing apparatuswith an overall thickness smaller than the conventional image capturingdevice and in compliance with the required thickness of a thin casing ofa notebook computer.

To achieve the aforementioned objective, the present invention providesa thin image capturing device, comprising:

a printed circuit board, having at least one electronic componentinstalled thereon, and electrically coupled by a circuit, and theprinted circuit board having a hole;

a light sensing element, embedded into the hole of the printed circuitboard, and having a sensing surface, wherein the bottom of the lightsensing element is attached onto the metal thin film by an adhesivelayer, and a first fixing adhesive filled into a gap between the lightsensing element and the printed circuit board for fixing the lightsensing element and the printed circuit board, and the light sensingelement and the printed circuit board includes a plurality ofcorresponding solder pads, and the printed circuit board and the lightsensing element are coupled to each of the corresponding solder pads byan gold wire for an electric connection, and a second fixing adhesive isapplied onto the solder pads of the printed circuit board forsurrounding and covering the attached position of the gold wire;

a transparent glass, attached onto the second fixing adhesive, alignedprecisely with the sensing area of the light sensing element, andcovered onto the light sensing element; and

a camera lens, having a lens module installed in a camera lens holderfor capturing an image, and the bottom of the camera lens holder beingaligned evenly with the transparent glass and fixed by a third fixingadhesive, and an image projected by the lens module installed in thecamera lens holder falling in the sensing area of the light sensingelement.

To achieve the aforementioned objective, the present invention providesa manufacturing method of a thin image capturing device, comprising thesteps of:

1. preparing a printed circuit board by manufacturing circuits andelectronic components on the front side of a printed circuit boardsubstrate and coupled to a solder pad;

2. forming a hole on the printed circuit board at a predeterminedposition of the printed circuit board;

3. attaching a metal thin film at least onto the backside of the printedcircuit board;

4. packaging a light sensing element, further comprising the steps of:

4-1. coating an adhesive layer on a surface of the metal thin film atthe bottom of the hole;

4-2. attaching the light sensing element by embedding the light sensingelement into the hole and attaching the light sensing element onto theadhesive layer;

4-3. fixing the light sensing element by applying a first fixingadhesive into the gap around the hole for the fixation;

4-4. bonding a gold wire by electrically coupling the light sensingelement and the solder pads of the printed circuit board;

4-5. sealing the surrounding of the hole by covering the solder padsaround the hole by a second fixing adhesive;

4-6. covering a transparent glass by aligning the transparent glass witha sensing area of the light sensing element, and attaching thetransparent glass onto the second fixing adhesive;

4-7. assembling a camera lens by evenly aligning the bottom of a cameralens holder with the transparent glass and attaching the camera lens tothe transparent glass, and fixing the camera lens at the printed circuitboard by a third fixing adhesive;

5. surface mounting the electronic components by electrically couplingthe front side of the printed circuit board to a plurality of electroniccomponents through the solder pads.

The aforementioned and other objectives and advantages of the presentinvention will become apparent by the detailed description of thefollowing preferred embodiments and the illustration of relateddrawings.

Of course, variations and modifications could be made by the personsordinarily skilled in the art without departing from the spirit of thepatent claims. It is noteworthy to point out that the drawings areprovided for the purpose of illustrating the present invention only, butnot intended for limiting the scope of the invention.

BRIEF DESCRIPTION OF THE INVENTION

FIG. 1 is a side view of the present invention;

FIG. 2 is a top view of the present invention;

FIG. 3 is a cross-sectional view of a light sensing element package ofthe present invention;

FIG. 4 is a schematic view of a pre-manufactured structure of a printedcircuit board of the present invention;

FIG. 5 is a schematic view of a structure of a printed circuit boardwith a hole and a locking hole in accordance with the present invention;

FIG. 6 is a rear view of a printed circuit board with an attached metalthin film of the present invention;

FIG. 7 is a front view of a printed circuit board with an attached metalthin film in accordance with the present invention;

FIG. 8 is a schematic view of a printed circuit board packaged with alight sensing element in accordance with the present invention;

FIG. 9 is a schematic view of a printed circuit board with an adhesivelayer coated into a hole in accordance with the present invention;

FIG. 10 is a schematic view of a printed circuit board having a lightsensing element attached onto an adhesive layer of the printed circuitboard in accordance with the present invention;

FIG. 11 is a schematic view of fixing a light sensing element onto aprinted circuit board in accordance with the present invention;

FIG. 12 is a schematic view of a printed circuit board electricallycoupled to a light sensing element and fixed by an adhesive inaccordance with the present invention;

FIG. 13 is a schematic view of a transparent glass fixed onto a printedcircuit board in accordance with the present invention;

FIG. 14 is a schematic view of a metal thin film extended to a lateralside of a printed circuit board in accordance with the presentinvention;

FIG. 15 is a schematic view of a metal thin film extended from a lateralside to a top side of a printed circuit board in accordance with thepresent invention;

FIG. 16 is a schematic view of a metal thin film extended from a lateralside of a printed circuit board and covered from the front in accordancewith the present invention;

FIG. 17 is a cross-sectional view of a first conventional packagestructure;

FIG. 18 is a cross-sectional view of a second conventional packagestructure; and

FIG. 19 is a cross-sectional view of a third conventional packagestructure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 to 13 for the first preferred embodiments ofthe present invention, this embodiment is provided for the purpose ofillustrating the structure and manufacturing method of the invention,but not intended for limiting the scope of the invention.

The present invention provides a thin image capturing apparatus as shownin FIGS. 1 to 3, and the image capturing device of this preferredembodiment comprises a printed circuit board 1, a plurality ofelectronic components 2, a light sensing element 3, a transparent glass4, and a camera lens 5.

In FIG. 3, the printed circuit board 1 has a solder pad 10 disposed on afront side of the printed circuit board 1, and the solder pad 10 iscoupled to a circuit (not shown in the figure) in the printed circuitboard 1, and the electronic components 2 are coupled to the solder pad10 of the printed circuit board 1 and electrically coupled by a circuitof the printed circuit board 1. The printed circuit board 1 has a hole11 with a shape and a size capable of containing the light sensingelement 3, and the size of the hole 11 is substantially equal to thesize of the light sensing element 3, and the printed circuit board 1includes a metal thin film 12 attached thereon, and the metal thin film12 of this preferred embodiment is attached onto the backside of theprinted circuit board 1 and has an area substantially equal to that ofthe printed circuit board, and the backside of the printed circuit board1 is covered onto the hole 11.

In FIG. 3, the light sensing element 3 includes a plurality of solderpads 30 corresponding to the printed circuit board 1. The bottom of thelight sensing element 3 is attached onto the metal thin film 12 by anadhesive layer 31, wherein the adhesive layer 31 of this preferredembodiment is made of an adhesive material which is an electricallyconductive adhesive, for grounding the light sensing element 3 throughthe metal thin film 12). A first fixing adhesive 32 is filled into thegap between the printed circuit board 1 and the light sensing element 3for fixing the printed circuit board 1 and the light sensing element 3.In other words, the first fixing adhesive 32 is filled between the hole11 of the printed circuit board 1 and the light sensing element 3. Afterthe first fixing adhesive 32 is cured, the printed circuit board 1 andthe light sensing element 3 are integrally formed. The solder pad 10 ofthe printed circuit board 1 and the solder pad 30 of the light sensingelement 3 are electrically coupled by a gold wire 33, and a secondfixing adhesive 13 is applied onto the solder pad 10 of the printedcircuit board 1 and covered onto the attached position of the gold wire33. The first fixing adhesive 32 and the second fixing adhesive 13 arenon-conductive adhesives.

In FIG. 3, the transparent glass 4 of this preferred embodiment isaligned precisely with the sensing area of the light sensing element 3,fixed onto the second fixing adhesive 13, and covered onto the lightsensing element 3 for protecting the light sensing element 3.

In FIG. 3, the camera lens 5 includes a lens module 51 installed insidea camera lens holder 50 for capturing an image. The bottom of the cameralens holder 50 is aligned evenly with the transparent glass 4 and fixedby a third fixing adhesive 52. The lens module 51 installed inside thecamera lens holder 50 projects images within the sensing area of thelight sensing element 4. The third fixing adhesive is a non-conductiveadhesive.

From the description above, the structure of this preferred embodimentof the present invention is illustrated. The manufacturing method of theimage capturing device of this preferred embodiment is described asfollows. The manufacturing method comprises the following steps:

(1) Prepare a printed circuit board 1. In FIG. 4, a circuit is formed ona printed circuit board substrate and a solder pad 10 is manufacturedfor coupling electronic components at the front side to form the printedcircuit board 1.

2. Form holes on the printed circuit board 1. In FIG. 5, after theprinted circuit board 1 is prepared, a hole 11 is formed at apredetermined position of the printed circuit board 1 for providing thespace of embedding the light sensing element 3. In this preferredembodiment, a locking hole 14 is formed on the printed circuit board 1.

3. Attach a metal thin film 12. In FIGS. 6 and 7, the metal thin film 12(which is an aluminum foil in this preferred embodiment) is prepared,and the metal thin film 12 at the backside of the printed circuit board1 is covered onto the hole 11.

4. Package a light sensing element 3. In FIG. 8, the light sensingelement 3 is packaged into the hole 11 of the printed circuit board 1,and this step further comprises the following steps:

4-1. Coat an adhesive layer 31. In FIG. 9, the adhesive layer 31 iscoated onto a surface of the metal thin film 12 at the bottom of thehole 11.

4-2. Attach the light sensing element 3. In FIG. 18, the light sensingelement 3 is embedded into the hole 11 and attached onto the adhesivelayer 31;

4-3. Fix the light sensing element 3. In FIG. 11, a first fixingadhesive 32 is applied into the gap around the hole 11 for the fixation.

4-4. Bond a gold wire 33. In FIG. 12, the gold wire 33 is provided forelectrically coupling the solder pad 30 of the light sensing element 3and the solder pad 10 of the printed circuit board 1.

4-5. Seal the surrounding of the hole 11. In FIG. 12, the second fixingadhesive 13 is provided for covering the position of the solder pad 10around the hole 11, and the second fixing adhesive 13 is coveredslightly on the attaching position of the gold wire 33.

4-6. Cover a transparent glass 4. In FIG. 13, the transparent glass 4 isaligned precisely with a sensing area of the light sensing element 3 andattached onto the second fixing adhesive 13.

4-7. Assemble a camera lens 5. In FIG. 3, the camera lens 5 is installedby evenly aligning the bottom of a camera lens holder 50 with thetransparent glass 4 and attaching and fixing the camera lens at theprinted circuit board by a third fixing adhesive 52.

5. Surface mount the electronic components 2. In FIGS. 7 and 8, thesolder pad 10 at the front side of the printed circuit board 1 iselectrically coupled to a plurality of electronic components 2 throughthe solder pad 10. In this preferred embodiment, this step is completedbefore the light sensing element 3 is packaged. Of course, this step canbe carried out after the light sensing element 3 is packaged.

The aforementioned image capturing device and the manufacturing methodthereof in accordance with the present invention have the followingadvantages:

1. In the manufacturing method of the image capturing device inaccordance with the present invention, the light sensing element 3 isembedded into the printed circuit board 1, and the transparent glass 4with a smaller thickness is fixed onto the printed circuit board 1 andcovered onto the light sensing element 3, so that the image capturingdevice of the present invention has a smaller overall thickness thanthose of the conventional image capturing devices to meet the thincasing requirement of the present notebook computers and overcome thedifficulty of installing the present casing into a 3.5 mm-thick casingas well as allowing the image capturing device with a higher pixel valueto be installed into the thin casing of the present notebook computers,so as to break through the bottleneck of the conventional installation.

2. In the screen of the present notebook computers, the frame of thescreen is minimized, so that the maximum width of the camera device islimited to 6 mm or 8 mm, and the printed circuit board is also limitedby these widths. Although the image capturing device of the presentinvention has a larger chip, the width deducting the width of the hole11 can still reserve an appropriate width from both sides in order toinstalling the circuit and bonding the wires. The present invention cancomply with the limitations of width and size.

3. When the camera lens 5 of the present invention is assembled, thetransparent glass 4 installed on the light sensing element 3 has beenaligned precisely with the sensing area, so that it simply requires tofix the bottom of the camera lens holder 50 to the transparent glass 4directly. Now, the lens module 51 in the camera lens 5 can be alignedprecisely with the sensing area of the light sensing element 3, so as toovercome the difficulty of assembling and aligning the conventionalcamera lens.

4. The metal thin film 12 attached onto the backside of the printedcircuit board 1 has a shielding effect, so that electromagneticinterference produced by the image capturing device or other externaldevices can be shielded.

Of course, the present invention can be implemented according to otherembodiments, but the variation is very small. With reference to FIG. 14for another preferred embodiment of the present invention, the metalthin film 12A having a size equal to or slightly smaller than thebackside of the printed circuit board 1 is attached, and then extendedfrom the backside to the lateral side of the printed circuit board 1. InFIG. 15, the metal thin film 12B is extended from the lateral side tothe top side of the printed circuit board 1. In FIG. 16, the metal thinfilm 12C is covered from the lateral side of the printed circuit board 1to the electronic component 2 installed on the front side of the printedcircuit board 1 and having the camera lens 5 exposed. The metal thinfilms 12A, 12B, 12C in accordance to the three preferred embodiments ofthe present invention respectively achieve the same effect of shieldingelectromagnetic interference.

While the invention has been described by means of specific embodiments,numerous modifications and variations could be made thereto by thoseskilled in the art without departing from the scope and spirit of theinvention set forth in the claims.

In summation of the above description, the present invention hereinenhances the performance than the conventional structure and furthercomplies with the patent application requirements and is submitted tothe Patent and Trademark Office for review and granting of thecommensurate patent rights.

What is claimed is:
 1. A thin image capturing apparatus, comprising: aprinted circuit board, having at least one electronic componentinstalled thereon, and electrically coupled by a circuit, and theprinted circuit board having a hole; a light sensing element, embeddedinto the hole of the printed circuit board, and having a sensingsurface, wherein the bottom of the light sensing element is attachedonto the metal thin film by an adhesive layer, and a first fixingadhesive filled into a gap between the light sensing element and theprinted circuit board for fixing the light sensing element and theprinted circuit board, and the light sensing element and the printedcircuit board includes a plurality of corresponding solder pads, and theprinted circuit board and the light sensing element are coupled to eachof the corresponding solder pads by an gold wire for an electricconnection, and a second fixing adhesive is applied onto the solder padsof the printed circuit board for surrounding and covering the attachedposition of the gold wire; a transparent glass, attached onto the secondfixing adhesive, aligned precisely with the sensing area of the lightsensing element, and covered onto the light sensing element; and acamera lens, having a lens module installed in a camera lens holder forcapturing an image, and the bottom of the camera lens holder beingaligned evenly with the transparent glass and fixed by a third fixingadhesive, and an image projected by the lens module installed in thecamera lens holder falling in the sensing area of the light sensingelement.
 2. The thin image capturing apparatus of claim 1, wherein theadhesive layer is made of an adhesive material which is an electricallyconductive adhesive.
 3. The thin image capturing apparatus of claim 1,wherein the metal thin film is attached onto the backside of the printedcircuit board with an area equal to or slightly smaller than the printedcircuit board, or extended to the top edge of the front side of theprinted circuit board, or covered onto the electronic componentinstalled on the front side of the printed circuit board with only thecamera lens being exposed.
 4. A manufacturing method of a thin imagecapturing apparatus as recited in claim 1, comprising the steps of: (1)preparing a printed circuit board by manufacturing circuits andelectronic components on a front side of a printed circuit boardsubstrate and coupled to a solder pad; (2) forming a hole on the printedcircuit board at a predetermined position of the printed circuit board;(3) attaching a metal thin film at least onto the backside of theprinted circuit board; (4) packaging a light sensing element, furthercomprising the steps of: (4-1) coating an adhesive layer on a surface ofthe metal thin film at the bottom of the hole; (4-2) attaching the lightsensing element by embedding the light sensing element into the hole andattaching the light sensing element onto the adhesive layer; (4-3)fixing the light sensing element by applying a first fixing adhesiveinto the gap around the hole for the fixation; (4-4) bonding a gold wireby electrically coupling the light sensing element and the solder padsof the printed circuit board; (4-5) sealing the surrounding of the holeby covering the solder pads around the hole by a second fixing adhesive;(4-6) covering a transparent glass by aligning the transparent glasswith a sensing area of the light sensing element, and attaching thetransparent glass onto the second fixing adhesive; (4-7) assembling acamera lens by evenly aligning the bottom of a camera lens holder withthe transparent glass and attaching the camera lens to the transparentglass, and fixing the camera lens at the printed circuit board by athird fixing adhesive; (5) surface mounting the electronic components byelectrically coupling the front side of the printed circuit board to aplurality of electronic components through the solder pads.
 5. Themanufacturing method of the thin image capturing apparatus as recited inclaim 4, wherein the step of forming the hole on the printed circuitboard further manufacturing a locking hole provided for passing andfixing the locking element.
 6. The manufacturing method of the thinimage capturing apparatus as recited in claim 4, wherein the metal thinfilm is attached onto the backside of the printed circuit board with anarea equal to the printed circuit board, or extended from the backsideto a lateral side of the printed circuit board, or further extended tothe top edge, or covered onto the electronic component installed on thefront side of the printed circuit board with only the camera lens beingexposed.